Abstract: The fuel injection valve is in particular a component of a reservoir fuel injection system and has a valve body and an electric control valve that controls the pressure which prevails in a control pressure chamber and acts at least indirectly on an injection valve member in its closing direction, wherein the control pressure chamber is connected to a high-pressure fuel source and can be connected by the control valve to a discharge chamber in order to open at least one injection opening. The control pressure chamber is embodied in a sleeve-shaped section of an insert piece inserted into the valve body and is connected to an inlet bore in the valve body by means of an annular chamber encompassing the section and a connecting bore provided in the valve body. The connecting bore intersects the inlet bore at an obtuse angle (&agr;) in a region that is offset from the annular chamber in the direction of the longitudinal axis of the valve body.

Abstract: A fuel injection valve having a valve member that is controlled by the pressure in a control pressure chamber and whose opening motion is influenced by way of a compensation pressure face of the valve member. This compensation pressure face adjoins a hydraulic chamber whose pressure is controlled with the aid of a piston which reduces the hydraulic initial stress of the hydraulic chamber, and keeps the fuel at an essentially constant value, and can compensate for volume changes of the hydraulic chamber by moving in opposition to a reference pressure.

Abstract: A fuel injector comprises a valve needle spring biased towards a seating. The valve needle defines a thrust surface orientated such that the application of fuel under pressure thereto applies a force to the needle urging the needle away from the seating. A valve is provided to control the supply of fuel to the thrust surface.

Abstract: A fuel injector includes an injector body that defines a nozzle outlet. A needle valve member is mounted in the injector body and moveable a lift distance between an open position in which the nozzle outlet is open, and a closed position in which the nozzle outlet is blocked. A piezoelectric actuator is mounted in the injector body and is moveable a piezo distance between an off position and an on position. A coupling linkage interconnects the needle valve member to the piezoelectric actuator such that a movement of the piezoelectric actuator is multiplied into a larger movement of the needle valve member.

Abstract: A fuel injector for use in an injector arrangement including a fuel pump having a pump chamber and a spill valve arrangement including a spill valve member which is engageable with a spill valve seating to control communication between the pump chamber and a low pressure drain. The fuel injector further comprises a valve needle which is engageable with a valve needle seating, a control chamber arranged such that the fuel pressure therein urges the valve needle towards its seating, a control valve arrangement, including a control valve member, for controlling the fuel pressure within the control chamber, and an actuator arrangement for controlling movement of the spill valve member and the control valve member. The actuator arrangement comprises a double pole actuator having a first armature which is movable with the spill valve member and a single pole actuator having a second armature which is movable with the control valve member.

Abstract: A fuel injection valve for internal combustion engines, having an axially movable valve member which, with its end oriented toward the combustion chamber, opens and closes a through flow cross section to at least one injection opening and which, with its end remote from the combustion chamber, protrudes into a fuel-filled spring chamber in which a valve spring is clamped, which acts on the valve member in the closing direction and is supported with its end remote from the valve member against a deflecting piston which, during the supply of high pressure fuel to the fuel injection valve, can be moved a certain distance into the spring chamber and thereby increases the initial stress force of the valve spring, and having a connecting conduit between the spring chamber and a low pressure fuel chamber. The connecting conduit between the spring chamber and the low pressure fuel chamber is embodied as a throttle bore in order to increase the injection opening pressure.

Abstract: An injection valve for a fuel injection system, for multistage control of the effective cross section of an injection opening. A spring/stop system with a first compression spring for a control valve for a control chamber, whose pressure determined the position of the valve shaft of an injection valve member. When a valve opens, the spring/stop system allows its valve tappet a first axial stroke, which is limited by a primary stop on an axially movable adapter. The axial mobility of the adapter allows the valve tappet, counter to the compressive force of a first compression spring, an additional, second axial stroke, which is limited by an end stop structurally connected to the housing. The valve tappet is urged in the closing direction of the control valve by a second compression spring braced against the housing of the injection valve, and in the closed state of the control valve the spring force of the second compression spring is less than that of the first compression spring.

Abstract: A fuel injector is provided which has an improved structure capable of adjusting fuel jet characteristics such as the quantity of fuel to be injected to an engine and a fuel injection time lag after the fuel injector is assembled. The fuel injector includes an air gap adjusting screw and a spring pressure adjusting screw. The air gap adjusting screw serves to change an air gap between a stator and an armature of a solenoid valve to adjust the quantity of fuel to a target one. The spring pressure adjusting screw serves to change a spring pressure urging a valve in a spray hole-closing direction to regulate a spray hole open duration, thereby adjusting the fuel injection time lag or the quantity of fuel.

Abstract: Disclosed is a fuel injection valve having at least two valve body parts, which each contact one another at a respective contact face and pressed against one another perpendicular to the contact face by a clamping device. An inflow conduit for fuel formed in both valve body parts passes through the contact faces, and a high fuel pressure prevails in it. At least one radially widened portion is embodied in the inflow conduit, near the contact face of at least one valve body part, so that this radially widened portion, as a result of the fuel pressure in the inflow conduit, undergoes an expansion in the axial direction. As a result, the region of the contact face surrounding the inflow conduit is pressed against the contact face of the contacting valve body part, so that the contact pressure of the contact faces increases, whereby the inflow conduit is thus better sealed off, and the force of the clamping device can be reduced.

Abstract: A pilot actuated spool valve assembly includes a valve body that defines a first passage, a second passage and a flow passage. A unitary pilot body is at least partially positioned in the valve body and has a first valve seat and a second valve seat. A pilot member is moveable in the pilot body between an up position in which the pilot member closes the first valve seat and a down position in which the pilot member closes the second valve seat. A spool valve member has a control hydraulic surface and is positioned in the valve body. It is moveable between a first position in which the first passage is open to the flow passage, and a second position in which the second passage is open to the flow passage. At least one of the valve body, the pilot body, the pilot member and the spool valve member define a control volume fluidly connected to the first passage when the pilot member is in one of its up position and its down position.

Abstract: An injection valve member for the closing and opening of injection orifices of a valve seat element is installed longitudinally adjustably in a central housing bore of a fuel injection valve. The opening and closing movement sequence of the injection valve member is controlled by a control device. A control piston operatively connected to the injection valve member is loaded, on the one hand, by the fuel system pressure prevailing in a high-pressure zone and, on the other hand, by the fuel control pressure in a control space. The high-pressure zone includes the central housing bore which is closed off sealingly by a control body fixed to the housing. The control space is arranged between the control body and a piston end face and is at least temporarily delimited radially by a control sleeve which is moveable transversely to the longitudinal axis of the housing.

Abstract: A fuel injector comprising a valve needle which is slidable within a bore, a surface associated with the valve needle defining, in part, a control chamber which communicates, through a restriction, with a supply passage. The fuel injector also includes an injection control valve controlling communication between the control chamber and a low pressure reservoir, and a drain valve controlling communication between the supply passage and the low pressure reservoir. The injection control valve and the drain valve include respective armatures moveable under the influence of a common electromagnetic actuator.

Abstract: A pump injector comprising a pumping chamber, a valve needle controlling communication between the pumping chamber and one or more outlet openings, and a spill valve controlling communication between the pumping chamber and a low pressure fuel reservoir, in use. The pump injector also comprises an inlet non-return valve arranged to permit fuel to flow from the fuel reservoir to the pumping chamber, in use, but substantially preventing fuel flow in the reverse direction. Alternatively, the pump injector may comprise an abutment piston engageable with the valve needle which defines, in part, a control chamber for fuel, and a control valve controlling communication between the pumping chamber and the control chamber.

Abstract: A fuel injector which has a double solenoid three-way or four-way spool valve that controls the flow of a working fluid that is used to move an intensifier piston of the injector.

Abstract: An actuation fluid control valve assembly for a hydraulically actuated fuel injector comprises a valve body defining a rotary valve bore and a spool valve bore. An actuator is connected with the valve body. A rotary valve member is rotatably disposed in the rotary valve bore and can be rotated in response to the actuator. A high-pressure fluid line, a spool bottom line, a check control line, and an actuator fluid drain all terminate in the rotary valve bore. At one rotary valve position, both the check control line and the spool bottom line are open to the high-pressure line. Moving the rotary valve from the first position to a second position opens the spool bottom line to the actuator fluid drain while keeping the check control line open to the high-pressure line. Moving the rotary valve from the second position to a third position opens the check control line as well as the spool bottom line to the actuator fluid drain.

Abstract: A valve comprises a valve body that includes an upper valve seat and a bore wall that defines a bore. A seat component is at least partially positioned in the bore and includes a lower valve seat. The seat component is radially out of contact with the bore wall. The upper valve seat and the lower valve seat are concentrically coupled via a valve member which is movable between the upper valve seat and the lower valve seat. The valve finds preferred application as a needle control valve in a fuel injector.

Abstract: A fuel injection valve for internal combustion engines, having a valve member that is displaceable axially outward counter to a restoring force in a bore of a valve body. On an end toward the combustion chamber, the valve member has a closing head. The closing head protrudes from the bore and forms a valve closing member and on a side toward the valve body has a valve sealing face. The valve closing member cooperates with a valve seat face, disposed on a face end toward the combustion chamber of the valve body. The valve closing member at least one injection opening on the closing head. The injection opening originating at a pressure chamber and outlet opening being covered, in the closing position of the valve member, by the valve body and being uncovered upon an outward-oriented opening stroke. A two-stage hydraulic stroke stop, which limits the opening stroke of the valve member and is embodied as a hydraulic damping chamber with a relief line that can be opened.

Abstract: The injection valve has a control valve with a control chamber in which a closing member is disposed. The closing member is pressed against a corresponding sealing seat by a pressure (e.g. fuel pressure) in the control chamber. The closing member merges into a rod that passes through a drain hole and is connected to a spring plate. The spring plate is preloaded against the housing by a compression spring in such a way that the closing member is pressed against an associated sealing seat. The closing member can be raised from the sealing seat by an actuator piston which rests against the spring plate.

Abstract: A valve comprises a valve member which is engageable with a first seating to control communication between first and second ports and a second seating to control communication between second and third ports. The second seating is provided upon a separate seating member.

Abstract: A fuel injector which has check valve that is hydraulically controlled by a control fluid. A volume of fuel is pressurized within a fuel chamber of the injector by an intensifier. The check valve controls the flow of fuel from the fuel chamber through at least one nozzle opening of a valve body. The flow of control fluid is controlled by a control valve which can move between a first position and a second position. When the control valve is at its first position, the control fluid creates an hydraulic force which moves the check valve to a closed position. When the control valve is at its second position, the control fluid moves the check valve to an open position to allow the pressurized fuel to be ejected or sprayed from the nozzle opening(s). The intensifier can also be hydraulically controlled by a control valve.

Abstract: A wear and scuff-resistant plunger for use in high pressure fuel system components in internal combustion engines is provided. The plunger, which is formed of a high thermal expansion, high hardness ceramic with a thermal expansion coefficient preferably greater than 6.times.10.sup.-6 /.degree. C. and a hardness preferably greater than 800 Kg/mM.sup.2, maintains a desired optimum minimal diametral clearance while avoiding excessive fuel leakage and efficient plunger function without scuffing or sticking under the high axial, side and pressure loads and variable quality fuels encountered in the fuel system operating environment. Preferred high thermal expansion, high hardness ceramics are zirconia, alumina-zirconia and alumina.

Abstract: A control valve for an injection valve for injecting fuel into an internal combustion engine is described. The injection valve has a control chamber which is connected via an inlet throttle to a high-pressure accumulator, and which can be connected via the control valve and an outlet throttle to an unpressurized return line to a fuel tank. The pressure prevailing in the control chamber acts on a movable nozzle body which is provided with a nozzle needle which releases and seals injection holes as the nozzle body moves. The control valve is constructed adjoining the control chamber, with the result that the pressure prevailing in the control chamber at a first operating surface also acts on the valve body of the control valve. The control valve has a valve chamber which is disposed opposite the control chamber and is connected to the control chamber via the outlet throttle and has a second operating surface, which is smaller than the first operating surface.

Abstract: An injector of intensified fuel injection type is disclosed in which a resin-made sealing member for sealing a clearance between a concave and a boosting piston fitted in the concave for reciprocating movement is protected from deterioration owing to high-pressure impulses occurring in the hydraulically actuating fluid in pressure chamber or in the fuel in the intensified chamber. The sealing member of resin-made O ring 44 prevents leakage of the hydraulically actuating fluid from the pressure chamber 8 to the spring chamber 30 through the clearance 27 between the enlarged concave and the boosting piston 119. A split metal ring 91 is arranged between the relatively sliding surfaces 49a, 49b of the enlarged concave 26 and the boosting piston 119 at any location between the pressure chamber 8 and the O ring 44.

Abstract: A solenoid actuated valve includes a valve body that defines a first passage and a second passage. The solenoid is attached to the valve body and has an armature. A multi-piece valve member is attached to the armature. At least one of the multi-piece valve member and valve body define a small passage and a large passage. The multi-piece valve member has a first configuration in which both the small and large passages are closed. The multi-piece valve member has a second configuration in which the small passage is open between the first passage and the second passage, but the large passage remains closed. The multi-piece valve member has a third configuration in which the large passage is open between the first passage and the second passage. The valve finds a preferred application as a control valve in a hydraulically-actuated fuel injector.

Abstract: An electronically controlled device, such as a fuel injector, includes a first solenoid and a second solenoid attached to the injector body. An electrical circuit is attached to the injector body, and includes a positive terminal and a negative terminal connected to the first solenoid and the second solenoid. The electrical circuit permits energization of one of the first solenoid and the second solenoid when electrical current flows in either direction between the first terminal and the second terminal. However, the electrical circuit permits energization of the other of the first solenoid and the second solenoid only when current flows in a single direction between the first terminal and the second terminal.

Abstract: A servo-controlled fuel injector is provided which includes a leakage limiting valve device for limiting the quantity of high pressure fuel available for leakage into the combustion chamber in the event the closed nozzle valve element fails to sealingly engage its seat between injection events. The servo-controlled fuel injector includes a control volume positioned adjacent an outer end of the nozzle valve element, a control volume charge circuit for supplying fuel to the control volume, a drain circuit for draining fuel from the control volume to a low pressure drain and an injection control valve positioned along the drain circuit for controlling the flow through the drain circuit so as to cause reciprocal movement of the nozzle valve element. The leakage limiting valve is integrated into the fuel injector body and positioned along a fuel transfer passage to block the flow of high pressure fuel to a nozzle cavity between injection events.

Abstract: A fuel injection valve for internal combustion engines, having a valve member that emerges outward from the valve body. At least two rows of injection ports one above the other are provided on the valve member, in the outward-oriented opening stroke of the valve member the injection parts are uncovered in secession. A two-stage hydraulic stroke stop, which limits the opening stroke travel of the valve member is embodied as a hydraulic damping chamber with openable relief. This relief is effected via at least two polished sections on the valve member which are openable in succession during the opening stroke motion of the valve member. At least one of the polished sections is connected to a low-pressure chamber, via a relief conduit containing a valve.

Abstract: A fuel injector (1) including a nozzle body (3) and a needle valve (4) liftably received in a nozzle body hole (21, 34) such that fuel flows to injection openings (16) of the nozzle body through a clearance between the nozzle body hole and needle valve. The clearance includes a larger clearance portion (37) and a smaller clearance portion (38) in series in a fuel flowing direction. The needle valve (4) has a collar (20) to almost plug the larger clearance portion (37) and a throttled fuel passage (22) is formed in the collar (20). Since the collar transversely extends in the larger clearance segment, it has a relatively large area subjected to the fuel pressure. Fuel pressure acts on this large area so that a large pressure difference is obtained across the collar during needle valve opening. Thus, it is possible to close the needle valve at a high speed.

Abstract: An electrically controlled hydraulic actuated fuel injector wherein the amount of return fuel flow is substantially reduced without adversely affecting injection valve operation. An improved control valve armature valve disk of faster acting construction is also included. In one embodiment, dual pressurizing passages of differing diameters provide lower total fuel flow to a control chamber than the outflow through a depressurizing passage controlled by a control valve. Upon full opening of the injection valve, all return fuel flow is supplied to the control chamber through the smaller pressurizing passage, thereby reducing the requirement for pressure fuel flow. Upon closing of the control valve, cutting off discharge through the depressurizing passage, both of the dual pressurizing passages help fill the control chamber to quickly close the injection valve.

Abstract: A piezoelectric injector for fuel-injection systems of internal combustion engines has a piezoactuator guided with spring pretensioning in a valve housing. The actuator presses a sealing piece onto its valve seat through an actuating part, with the actuating part consisting of a pressure pin passing through the piezoactuator and having a head part resting on piezoactuator. The pressure pin and piezoactuator are of the same length and are made of the same ceramic material, in operation the sealing piece is lifted off its valve seat by piezoactuator which is expanded when in the charged state.

Abstract: A fuel injector includes an injector body that defines a nozzle outlet. A needle valve member is mounted in the injector body and moveable a lift distance between an open position in which the nozzle outlet is open, and a closed position in which the nozzle outlet is blocked. A piezoelectric actuator is mounted in the injector body and is moveable a piezo distance between an off position and an on position. A coupling linkage interconnects the needle valve member to the piezoelectric actuator such that a movement of the piezoelectric actuator is multiplied into a larger movement of the needle valve member.

Abstract: A hydraulically actuated dual fuel injector for an internal combustion engine. More particularly, the application pertains to a hydraulically actuated injector for injecting controlled quantities of a first fuel and of a second fuel into an internal combustion diesel engine at different times.

Abstract: The fuel injection device of this invention utilizes the fuel pressure in the balance chamber for closing the open-close valve to prevent fuel leakage from the open-close portion. When the open-close valve is opened, the valve stem of the open-close valve piercing through the exhaust passage in the control member moves toward the balance chamber. The valve head opens the port of the exhaust passage on the balance chamber side to lower the fuel pressure in the balance chamber, with the result that the needle valve lifts injecting the fuel. When the open-close valve is closed by the return spring, the fuel pressure in the balance chamber acts on the valve head to urge the open-close valve in the valve closing direction, preventing the leakage of fuel through the open-close valve.

Abstract: An actuation fluid control valve for a hydraulically actuated fuel injector comprises an injector body having an actuation fluid control passage, a low pressure actuation fluid drain passage, and a high pressure actuation fluid supply passage for accepting high pressure actuation fluid into the fuel injector. An actuator is attached to the injector body. A rotatable valve member includes a first valve passage and a second valve passage and is disposed in the injector body such that high pressure actuation fluid entering from the high pressure actuation fluid supply passage will not bias the rotatable valve member either toward the first position or toward the second position.

Abstract: An actuation fluid control valve for a hydraulically actuated fuel injector comprises an injector body having a high pressure actuation fluid supply passage for admitting high pressure hydraulic actuation fluid into the fuel injector, an actuation fluid control passage for admitting the high-pressure hydraulic actuation fluid to commence fuel injection, a low-pressure actuation fluid drain passage for draining the hydraulic actuation fluid from the fuel injector, and a check valve fluid control passage for admitting the high pressure hydraulic actuation fluid to terminate fuel injection. An actuator is attached to the injector body. A rotatable valve member includes a first valve passage and a second valve passage and is disposed in the injector body such that high pressure actuation fluid entering from the high pressure actuation fluid supply passage will not bias the rotatable valve member either toward the first position or toward the second position.

Abstract: A hydraulically-actuated fuel injector includes an injector body that defines an upper actuation fluid cavity, a lower actuation fluid cavity, an actuation fluid inlet, a spill passage, a piston bore and a nozzle outlet. A control valve member is positioned in the injector body and moveable between a first position and a second position. An intensifier piston is positioned in the piston bore and moveable between a retracted position and an advanced position. The piston has a primary hydraulic surface exposed to fluid in the upper actuation fluid cavity, and an opposing hydraulic surface exposed to fluid in the lower actuation fluid cavity. The upper actuation fluid cavity is open to the actuation fluid inlet, and the lower actuation fluid cavity is open to the spill passage when the control valve member is in its first position. The spill passage is blocked when the control valve member is in its second position.

Abstract: An accumulator fuel injection apparatus for an internal combustion engine is provided which includes a solenoid-operated fuel injector. The fuel injector includes a solenoid valve and a needle valve. The solenoid valve establishes and blocks fluid communication between a pressure control chamber supplied with fuel pressure from a fuel inlet and a drain passage formed in a valve body to change fuel pressure within the pressure control chamber, thereby bringing the needle valve into engagement with and disengagement from a spray hole. The fuel injector also has a first orifice disc and a second orifice disc installed within the valve body. The first orifice disc has formed therein a first orifice which provides a first flow resistance to fuel flowing from the fuel inlet into the pressure control chamber.

Abstract: A fuel injector is described which comprises an outer valve needle biased into engagement with a seating to control the supply of fuel to one or more outlet apertures, an inner valve member slidable within a bore formed in the outer valve needle and engageable with a seating to control the fuel supply to one or more further outlet apertures, the inner valve member and outer valve needle together defining a control chamber. A control valve controls the operation of the inner valve member by controlling the fuel pressure within the control chamber.

Abstract: A fuel injector includes an injector body that defines a nozzle outlet, and a needle control chamber that is in fluid communication with a needle control passage. A needle valve member is positioned in the injector body, and has a closing hydraulic surface exposed to fluid pressure in the needle control chamber. The needle valve member is moveable between a first position in which the nozzle outlet is blocked, and a second position in which the nozzle outlet is open. The needle control passage includes a dual flow rate orifice. Hydraulic fluid is displaced into the needle control chamber through the dual flow rate orifice when the needle valve member moves from its second position toward its first position. Hydraulic fluid is displaced out of the needle control chamber through the dual flow rate orifice when the needle valve member moves from its first position toward its second position. A compression spring is operably positioned to bias the needle valve member toward its first position.

Abstract: A fuel injector comprises a valve needle biased into engagement with a seating by a spring, a fuel supply line arranged to permit fuel under pressure to be supplied towards the seating, a control chamber communicating through a restricted flow passage with the supply line, and a control valve arranged to control the fuel pressure within the control chamber, wherein the control chamber is defined, in part, by a surface associated with the valve needle, the surface being orientated such that the application of high pressure fuel to the control chamber applies a force to the surface acting in a direction opposing the action of the spring on the valve needle.

Abstract: A fuel injector that contains no springs and is controlled by a valve assembly that has more than two modes of operation. The fuel injector includes a housing which has a supply port, a drain port and a cylinder passage that is in fluid communication with an intensifier. The intensifier moves between a first position and a second position within a fuel chamber. The fuel chamber is coupled to a fuel port. Movement of the intensifier into the second position pressurizes the fuel within the fuel chamber. The pressurized fuel opens a needle valve so that fuel is ejected through an aperture of the housing. The cylinder passage is coupled to a first fluid control valve and a second fluid control valve. Each control valve can be actuated between a closed position and an open position.

Abstract: A fuel injector includes a tip member having a further member establishing an interference fit about an outer surface thereof at an injection end to minimize the possibility of fracture or other failure.

Abstract: A hydraulically-actuated fuel injector includes an injector body that defines a high pressure inlet, a low pressure drain, an upper actuation fluid cavity, a lower actuation fluid cavity, and a nozzle outlet. A piston is positioned in the injector body and moveable between a retracted position and an advanced position. A control valve is attached in the injector body and includes a spool valve member that is moveable between a first position and a second position. When the spool valve member is in its first position, the piston is biased toward its retracted position since the upper actuation fluid cavity is open to the low pressure drain, but the lower actuation fluid cavity is open to the high pressure inlet. During an injection event, the spool valve member is moved to its second position where the upper actuation fluid cavity is open to the high pressure inlet, but the lower actuation fluid cavity is open to the low pressure drain.

Abstract: A fuel injection nozzle includes a lift piece located on the side of a nozzle needle. A protrusion of the lift piece and the distal end of a push rod are held by a spring seat with a specified clearance therebetween as a prelift. The adjustment of the prelift can be performed only by taking out the lift piece to be adjusted, so that the adjusting work of the prelift, accompanied with disassembly of the fuel injection nozzle becomes easy and fuel injection characteristics are improved.

Abstract: A fuel injector solenoid includes a solenoid coil disposed in a stator, a flux conduction element carried by the stator and a flux blocking element disposed within a central recess of the stator and surrounded by the flux conduction element. First and second armatures are disposed in the central recess on opposite sides of the flux blocking element.

Abstract: An injector is disclosed which comprises a nozzle body arranged to receive fuel under pressure from a pumping chamber. An injection control arrangement in the form of a valve controls injection timing, and a drain control arrangement in the form of a valve controls communication between the pumping chamber and a fuel reservoir. An electromagnetic actuator controls operation of both valves, the actuator including a single, common armature which is associated with both of the valves.

Abstract: An injection nozzle comprises a valve needle engageable with a seating. The needle includes a surface arranged such that when the needle occupies a fully lifted position, part of the surface is exposed to the fuel pressure within a control chamber whilst a second part of the surface is exposed to the fuel pressure within a second chamber. Independent restricted passages provide communication between the control and second chambers and a supply line. A control valve communicates with the second chamber to control operation of the injection nozzle. The control valve is actuated by an electromagnetic actuator having a core arrangement--armature air gap of tapering axial length.

Abstract: An injection valve arrangement for injecting a pressure medium into a combustion chamber of an internal combustion engine comprises a valve body formed with a feed duct and an actuation chamber, and an elongated valve member fitted in the valve body and movable in the valve body between an open position and a closed position. The valve member is formed with an internal chamber which is in communication with the feed duct and is also formed with one or more nozzle orifices which provide fluid communication between the internal chamber and the combustion chamber when the valve member is in the open position. The valve member has a piston surface bounding the actuation chamber such that force acting on the valve member due to pressure in the actuation chamber urges the valve member toward its open position against the force of a spring.

Abstract: An improved nozzle assembly for servo-controlled fuel injectors is provided which includes a needle valve control device including a rate shaping control device for effectively producing a predetermined time varying change in the flow rate of fuel injected into the combustion chamber during an injection event so as to reduce emissions. The rate shaping control device includes an injection control valve positioned along a drain circuit connected to a control volume positioned at one end of the needle valve element. The injection control valve includes an actuator for controlling the flow of fuel through the drain circuit to variably control the rate of movement of the needle valve element between the open and closed positions so as to provide the desired shaping to the flow rate of fuel into the combustion chamber.

Abstract: A unit fuel injector adapted to receive fuel from a fuel supply at relatively low pressure and adapted to inject fuel at relatively high pressure into the combustion chamber of an internal combustion engine is provided, comprising an injector body having a first internal bore and an injector orifice and a plunger mounted for reciprocating movement within the first internal bore to define a variable volume fuel pressurization chamber including a cam actuated upper plunger portion and a lower plunger portion mounted in the first internal bore between the variable volume fuel pressurization chamber and the upper plunger portion. While the upper plunger portion is in its retracted position, low pressure fuel from the fuel supply is supplied to the variable volume fuel pressurization chamber.